1. Field of Invention
The present invention relates to improved fastening means for a pair of flaps or the like, and more particularly to improved magnetic fastening means for use in place of buttons, snaps, and the like.
2. Brief Summary of the Prior Art
Conventional fastening means such as buttons, snaps, and the like, are presently and will probably remain for the forseeable future, the most widely used devices for releasably joining a pair of fabric flaps or the like. The reasons for this are simple. Conventional fastening devices are generally uncomplicated devices which are easy to use, and inexpensive to manufacture and install. Despite these facts, however, there remain certain situations in which, and certain individuals to whom, the use of such conventional fastening means are not particularly well adapted. Thus, for example, in the fashion context the visible presence of a button or snap may be considered to be aesthetically unsatisfactory, yet the closure required may not be adapted for the use of a zipper or other conventionaL device. Similarly, conventional buttons and snaps in other contexts may be inappropriate where exposure to the elements may cause rusting, leakage, or other forms of damage. Various attempts to alleviate these problems are present in the art, including the use of comparatively expensive weatherproofing materials and the use of protective flaps which render the operation of the fastener somewhat awkward. Also, for some people, most notably the elderly, the very young, and those who for one reason or another lack normal manual dexterity, the operation of conventional fastening means, including zippers and even Velcro fasteners as well as conventional buttons and snaps, is extremely difficult.
In response to the above deficiencies, fastening means relying upon magnets to releasably hold a pair of flaps or the like together have been developed in an attempt to facilitate the fastening and unfastening operations. Heretofore, such devices have relied upon direct flush abutting contact between magnetic surfaces of opposite polarities, or between a magnetic surface and a ferromagnetic surface, to establish the desired releasable locking engagement.
As used herein the terms "magnetic" and "ferromagnetic" are used to distinguish between permanently magnetized surfaces and surfaces which may be temporarily magnetized when in contact with or in close proximity to a permanent magnet, respectively. U.S. Pat. No. 3141216 to Brett, issued July 21, 1964, is exemplary of such devices. It will be understood, however, that such prior devices have been found to be economically impractical due to their weight in comparison to conventional devices, their thickness in comparison to the flaps they are intended to join and the inherent difficulty of mounting the operative fastening elements so as to allow direct flush abutting contact therebetween. Brett shows the later of these problems clearly. Thus, if the operative elements are to be located in holes in the flaps there must be some sort of mechanical link between the flap and the fastener to maintain the fastening elements in position. In such a case the periphery of the holes in the flaps is the weakest portion of the link and is vulnerable to tearing with a resultant dislodging of the fastener. Alternatively, if the fastener is mounted without making a hole in the flap, for example by crimping a portion of the flap between the operative elements and a cap, the operation of the device itself will require the exertion of forces which tend to pull the fastener apart thereby dislodging it from the flap.